Magnetic interrupter



Jan. 9, 1934. w. Pf' E-AR Er AL 1,943,240

MAGNETIC INTERRUPTER F1164 sept. 27, 1952 2 sheets-sheet 1 :QW @l 4 4 /0l U1 .L E

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Application September 27, 1932 Serial No. 635,057

8 Claims.

This invention relates to mechanical interrupter unitsfor electricalcircuits a-ndl more particularly, to such devices of the magnetic typeadapted rapidly to make and break electrical circuits such as that of apotential changer.

A general object of the present invention is the provision of such adevice which is quiet, steady and efllcient in operation, can be readilyduplicated in commercial production, and which is designed to eliminatethe transfer therefrom of high potential disturbances and interferenceeffacts, shielded to reduce electro-magnetic and electro-staticdisturbances set up by the operation thereof and is constructed so as tobe readily removable as a unit from any circuit in which it is used.

More specific objects of the invention are the provision ina potentialchanger of such a device formed as a removable unit to allow readysubstitution of this unit so that continuous operation of the potentialchanger may be had while the necessary adjustments or replacements arebeing made in the interrupter unit, this removable feature being securedby the use of a prong base adapted to cooperate with receptive jacks inthe circuit of the potential changer; the provision of a sound isolatingcasing for the inter- Nul rupter unit providing a resilient mount forthe in` terrupter unit which cooperates with flexible circuit terminalsbetween the interrupter unit and the prong base to prevent the transferof mechanical vibration and noise to and from the interrupter unit andthe use of inertia means on the frame of the interrupter unit such asmasses of metal of high specific gravity to steady the mechanicaloperation in the reed system thereof; the provision of a metallic case,preferably adapted to be grounded and formed preferably from a materia]having good electrical conductivity and high magnetic permeability, toprevent the transfer of disturbance effects from the interrupter unit tothe circuit of the potential changer attributable to high frequencypotentials set up by the recurrent arcing and sparking of the contactpoints and the operation of the magnetic interrupter as a whole which isa potential radiator of electro-magnetic and electro-staticdisturbances.

Another object of the invention is the provision in such a removableunit of a capacitor unit shunted around all of the circuit elements ofthe interrupter, a resistor yunit bridged across the contact points andanother capacitor unit bridged across the contact points, the capacitorunits preferably being encased in a container adapted to 65 be securedto the base of the interrupter to serve as a mass to steady themechanical operation in the reed system, the capacitor unit and theresistor unit being enclosed within the casing of the removable unit toallow the use of relatively short and heavy leads thereto and to causethe metallic casing of the removable unit to act as a metallic shieldfor the capacitor units.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts, which will beexemplified in the construction hereinafter set forth and the scope ofthe application which will be indicated in the claims.

For a fuller understanding of the nature and objects of the inventionreference should be had to the following detailed description taken incon nection with the accompanying drawings, in which:

Fig. l is a front elevational view with parts in section of areinovableunit of the present invention provided with a sound isolating casing anda metallic case enclosing a magnetic interrupter;

Fig. 2 is a side elevational view with parts in section of the removableunit depicted in Fig. l;

Fig. 3 is a sectional view, with parts broken away, taken on line 3--3of Fig. 1;

Fig. 4 is a sectional view taken on line 4--4 of Fig. 2;

Fig. 5 is a front elevational view with parts in section of a modifiedform of the removable unit depicted in Figs. 1, 2, 3 and 4;

Fig. 6 is a side elevational view with parts in section of the removableunit depicted in Fig. 5;

Fig. 7 is a sectional view taken on line '7 7 of Fig. 6;

Fig. 8 is a perspective view of the removable unit depicted in Figs. 5,6 and '7.

The usual magnetic nterrupters are characterized by structures of lowefliciency due to transfer of mechanical vibration and noise to and fromthe interrupter unit, unsteady mechanical operaition of the reed armthereof, and transfer of disturbance eiects from the interrupter unit tothe 100 circuit of potential changers attributable to high frequencypotentials set up by the recurrent arcing and sparking of the contactpoints and the operation of the magnetic interrupter as a whole which isa potential radiator of electro-magnetic 105 and electro-staticdisturbances, all of which are undesirable when such a device is to beused in the circuit of a potential changer such, for example, as adevice for changing low potential direct current to direct current ofhigh poten- 110 tials suitable for use as the B supply of a radioreceiver disclosed and described in the copending application of WilliamP. Lear, Marvin E. Nulsen and Raymond S. Yoder, Serial No. 635,056 ledSeptember 27, 1932, and assigned to the same assignee.

The present invention eliminates these and other difficulties of theprior art, particularly in potential changer devices referred to abovewherein such a mechanical interrupter is used in the primary circuit tomake and break periodically the iiow of direct current through theprimary of a transformer so that an alternating current of desiredpotential will be set up in the secondary of the transformer whichalternating current can then be delivered to any desired device orrectified and filtered to supply direct currents of any desiredpotentials different from the potential of the direct current source ofthe primary circuit.

Referring to the drawings, and, more particularly, to Figs. 1, 2, 3 and4 wherein is depicted a removable mechanical interrupter unit 10. Thisunit is provided with a metallic base member 1l having a hole thereinover which is secured a sheet of insulating material 12 secured to thebase member 11 by any suitable means, such as rivets 13. The sheet ofinsulating material 12 is provided 'with circuit terminal prongs 14, 15,1 and 17, prong 14 being connected to the wire 18, prong 15 beingconnected to the wire 19, prong 16 being connected to the Wire 20 andprong 17 being connected to a wire 21 soldered to the metallic base 11as depicted in Fig. 3.

A layer of resilient material 22, preferably of sponge rubber, ispositioned on the base 11 and a casing 23 of sound isolating material,preferably sponge rubber, is fitted over the interrupter device tocooperate with the resilient layer 22 to form a sound isolatingenclosure for the interrupter, the wires 18, 19 and 20 are preferablyformed from flexible stranded cable to minimize mechanical transmissionof vibration to and from the enclosed interrupter device.

The relatively stationary structure of the interrupter device must begiven sufficient inertia to steady the mechanical oscillation of thereed system since the interrupter device has been provided with aresilient mount. This inertia may be obtained by making the frame or thesupports thereof, or the magnetic coil of sufficient size and weight toobtain the desired mass but is preferably obtained by securing to theframe masses of metal of high specic gravity such as lead. These massesmay be provided in the form of spiders 24-24 secured at opposite ends toa frame 25 of the magnetic interrupter and shaped to insure a properpositioning o the interrupter device within the casing 23 as depicted inFigs. 1 and 2 and, more particularly, in Fig. 4.

The enclosed interrupter unit is preferably provided with a case 26formed from metallic material preferably a metallic material having goodelectrical conductivity and high magnetic permeability, such as pureiron, to form with the base 11 of similar material a grounded shield toavoid the transfer from the interruptor unit to portions of the circuitin which this unit is connected of disturbance eects, the interrupterunit including the electro-magnetic coil being a potential radiator ofelectro-magnetic and electro-static disturbances. The grounding of themetallic case 26 is obtained by grounding the receptive jack adapted toreceive the prong 17.

In the magnetic interrupter an auxiliary reed 27 is shown carrying onecircuit contact point 28 to cooperate with another circuit contact point29 mounted upon a vibratory reed 30. The vibratory reed 30 is mounteddirectly upon the base 25 as shown, while the auxiliary reed 27 ismounted upon the support 3l suitably insulated from the base 25. Thewire 18 is directly connected to the base 25. The wire 19 is connectedto one end of a magnetic coil 32, the other end of which is connected bya wire 33 to the auxiliary reed support 3l. The wire 20 is directlyconnected to auxiliary reed support 3l so that suitable means areprovided for bridging a resistor and a capacitor unit across the circuitcontact points 28 and 29 by connecting them between the prong receptivejack for the prong 14 and the prong receptive jack for the prong 16` Anadditional capacitor unit may be shunted around all of the elements ofthe interruptor unit by connecting it between the prong receptive jackfor the prong 14 and the prong receptive jack for the prong l5. Thesefeatures and the circuit are more completely described in the copendingapplication referred to above since it constitutes subject matterforming a part of the invention claimed therein.

A modified form of the removable interrupter unit is depicted in Figs.5, 6, 7 and 8. In this form the above referred to shunted capacitor unitfor all of the elements of the interrupter and the bridged resistor unitand capacitor unit for the circuit contact points 28 and 29 are enclosedwithin the sound isolating casing 23 and the metallic case 26. The base34 of the metallic case 26 is provided with a portion 35 forming a sideof the metallic case as depicted in Figs. 6 and 8 and holes are providedin the portion 35 over which is fitted the sheet of insulating materiall2. The portion 35 is additionally provided with ears 36-36 to aid inanchoring this removable unit. The metallic base 34 is provided with acup-shaped resilient member 37 preferably of sponge rubber adapted tocooperate with the sound isolating casing 23. The resilient members 37and 23 serve as sponge rubber elements between the metallic case 61 andthe vibratory interrupter unit to position the latter within the case 61and to prevent transfer thereto of vibration from the vibratoryinterrupter unit.

The container 38 carries a shunted capacitor unit for all of theinterrupter elements and a bridged capacitor unit for the circuitcontact points, the shunted capacitor unit being provided withrelatively short heavy leads 39 and 40, the lead 39 being connected tothe wire 19 which is connected to the prong I5, the lead 40 beingsecured to the frame 25 with the wire 18 which is connected to the prong14'. The bridged capacitor unit is connected by short heavy leads 41 and42 to the auxiliary reed support 31 and to the frame 25 respectively. Aresistor unit 43 is bridged across the circuit contact points 28 and 29by connecting the respective ends thereof to the auxiliary reed support31 and to the frame 25.

The capacitor units in the container 38 are 1 as possible to theelements of the magnetic interrupter thereby improving the eillciency ofthe elimination of the disturbances set up by the operation of themagnetic interrupter. This eiliciency is further improved by theelectrostatic and magnetic shield formed by the metallic case 26grounded in any desired manner. In additionthe capacitor units togetherwith the container 38 perform the functions of the inertia and centeringspider 24 of the first modification.

It will thus be seen that the device of the present inventionefficiently attains the objects set forth above.

Since certain changes may be made in the above construction anddifferent embodiments of the invention could be made without departingfrom the scope thereof, it is intended that all matter contained in theabove description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

Having described our invention, what we claim as new and desire tosecure by Letters Patent, is:

l. In a potential changer operated with a direct current source as theB'T supply of an automobile radio, an article of manufacture consistingof a removable mechanical interrupter unit comprising a base of ironhaving prongs insulated therefrom and adapted to cooperate withreceptive jacks in the electrical circuit of the potential changer, amagnetic interrupter electrically connected to the prongs of said base,a layer of resilient material interposed between said magneticinterrupter and said base, a sound isolating casing to cooperate withsaid layer of resilient material to form a substantially sound-proofenclosure for said interrupter, spiders of metal of high specificgravity secured to the ends of the frame structure of said interrupterto center said interrupter in said c asing and to steady the mechanicaloscillation of the reed system thereof, and a case of iron to cooperatewith said base to form an enclosing iron case for said magneticinterrupter.

2. In a potential changer operated with a direct current source as the Bsupply of an automobile radio, an article of manufacture consisting of aremovable mechanicalinterrupter unit comprising a base of iron havingprongs insulated therefrom and adapted to cooperate with receptive jacksin the electrical circuit of the potential changer, an enclosed magneticinterrupter having inertia means on the relatively stationary structurethereof, resilient means interposed between said magnetic interrupterand said base, a sound isolating casing to cooperate with said resilientmeans to form a substantially sound proof enclosure for saidinterrupter, flexible electrical connections between said magneticinterrupter and the prongs of said base to cooperate with said resilientmeans to prevent the transmission of mechanical vibration and noise toand from said interrupter unit, and a case of iron to cooperate withsaid base to form an enclosing iron case for said magnetic interrupter.

3. In a potential changer adapted for use with a direct current sourceas the 13" supply of an automobile radio, an article of manufactureconsisting of a mechanical interrupter unit comprising a magneticvibratory interrupter including a mass of metal of high specific gravityto steady the mechanical oscillations thereof, an iron case enclosingsaid vibratory interrupter, and sponge rubber elements between said ironcase and said vvibratory interrupter cooperating with said mass and saidcase to position said vibratory interrupter within said case and toprevent transfer of vibrations from said vibratory interrupter to saidiron case.

4. In a potential changer adapted for use with a direct current sourceas the B supply of an automobile radio, an article of manufactureconsisting of a mechanical interrupter unit comprising a magneticinterrupter, a sound isolating casing surrounding said magneticinterrupter, and a grounded case of metallic material having goodelectrical conductivity and high magnetic permeability encl-osing saidsound isolated magnetic interrupter. l

5. In a potential changer adapted for use with a direct current sourceas the "B supply of an automobile radio, an article of manufactureconsisting of a mechanical interrupter unit comprising a magneticinterrupter, a casing of sponge rubber surrounding said magneticinterrupter, and a grounded iron case enclosing said rubber encasedmagnetic interrupter.

6. In a potential changer adapted for use with a direct current sourceas the B" supply of an automobile radio, an article of manufactureconsisting of a removable mechanical interrupter unit comprising amagnetic interrupter, a sound isolating casing surrounding said magneticinterrupter, a metallic case enclosing said sound isolated magneticinterrupter, and a prong base forming a portion of said metallic caseand adapted to cooperate with receptive jacks in the electrical circuitof the potential changer to connect therein said magnetic interrupterelectrically connected to the prongs of said base.

'7. In a potential changer adapted for use with a direct current sourceas the B supply of an automobile radio, an article of manufactureconsisting of a removable mechanical interrupter unit comprising amagnetic interrupter, a casing of sponge rubber surrounding saidmagnetic interrupter, a grounded -iron case enclosing said rubberencased magnetic interrupter, and a prong base forming a portion of saidmetallic case and adapted to cooperate with receptive jacks in theelectrical circuit of the potential changer to connect therein saidmagnetic interrupter electrically connected to the prongs of said base.

8. In a potential changer adapted for use with a direct current sourceas the B supply of an automobile radio, an article of manufactureconsisting of a removable mechanical interrupter unit comprising a baseof iron having prongs insulated therefrom and adapted to cooperate withreceptive jacks in the electrical circuit of the potential changer, amagnetic interrupter electrically connected to the prongs of said base,a sound isolating casing surrounding said magnetic interrupter, and acase of iron adapted to cooperate with said iron base and a prong ofsaid base to form a grounded case of good electrical conductivity .andhigh magneticl permeability about said sound isolated magneticinterrupter, said unit including a mass of metal of high specificgravity to steady the mechanical oscillations of the reed systemthereof.

WILLIAM P. LEAR.

MARVIN E. NULSEN.

